U.S. patent number 4,945,078 [Application Number 07/359,207] was granted by the patent office on 1990-07-31 for mixed basic metal sulfide catalyst.
This patent grant is currently assigned to Institute of Gas Technology. Invention is credited to S. Peter Barone, Erek J. Erekson, Anthony L. Lee, Irvine J. Solomon.
United States Patent |
4,945,078 |
Erekson , et al. |
July 31, 1990 |
Mixed basic metal sulfide catalyst
Abstract
A mixed basic metal sulfide catalyst having the formula: wherein
A is an alkali metal selected from lithium, sodium, potassium,
rubidium, cesium and mixtures thereof; B is a cation which has an
ionization state 1 greater than the ionization state of C; B is
selected from scandium, yttrium, lanthanum, actinium, aluminum,
boron and mixtures thereof when C is selected from beryllium,
magnesium, calcium, strontium, barium, radium, zinc, cadmium,
mercury and mixtures thereof and B is selected from titanium,
zirconium, hafnium, silicon and mixtures thereof when C is selected
from scandium, yttrium, lanthanum, actinium, aluminum, boron and
mixtures thereof; x and y are in mole fractions of z such that when
z=1 then x=0.001 to 0.25, and y=0.001 to 0.25; and q is a number
necessary to maintain charge balance with S being sulfur. The
catalyst is useful for oxidative coupling of methane and aliphatic
and alicyclic hydrocarbon compounds with an aromatic compound to
produce higher molecular weight hydrocarbons; and for
dehydrogenating hydrocarbon compounds to produce unsaturated
aliphatic and alicyclic chains.
Inventors: |
Erekson; Erek J. (LaGrange,
IL), Lee; Anthony L. (Glen Ellyn, IL), Barone; S.
Peter (Hoffman Estates, IL), Solomon; Irvine J.
(Highland Park, IL) |
Assignee: |
Institute of Gas Technology
(Chicago, IL)
|
Family
ID: |
27390194 |
Appl.
No.: |
07/359,207 |
Filed: |
May 31, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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274415 |
Nov 21, 1988 |
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274499 |
Nov 21, 1988 |
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274454 |
Nov 21, 1988 |
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172808 |
Mar 28, 1988 |
4826796 |
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Current U.S.
Class: |
502/202; 502/216;
585/500 |
Current CPC
Class: |
B01J
23/00 (20130101); B01J 23/02 (20130101); B01J
23/06 (20130101); C07C 2/84 (20130101); C07C
5/3332 (20130101); C07C 5/3332 (20130101); C07C
15/42 (20130101); C07C 2521/02 (20130101); C07C
2521/10 (20130101); C07C 2523/02 (20130101); C07C
2523/04 (20130101); C07C 2523/06 (20130101); C07C
2523/10 (20130101); C07C 2523/12 (20130101); C07C
2527/04 (20130101) |
Current International
Class: |
B01J
23/02 (20060101); B01J 23/06 (20060101); B01J
23/00 (20060101); C07C 2/84 (20060101); C07C
2/00 (20060101); C07C 5/333 (20060101); C07C
5/00 (20060101); B01J 021/02 (); B01J 023/02 ();
B01J 023/04 (); B01J 027/04 () |
Field of
Search: |
;502/202,216
;585/500 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Keller, G. E. and M. M. Bhasin, J. of Catalysis 73, 9-19 (1982).
.
Hinsen, W. and M. Baerns, Chem.-Ztg., 107, 223-226 (1983). .
Hinsen, W., W. Bytyn and M. Baerns, Proc. 8th Int. Congr. Catal.,
Berlin, III 581-592 (1984). .
Chemical Abstracts (USSR): 97:127153K (1982); 99:70137t (1983);
101:74734t (1984); and 101:38205n (1984). .
Kirk-Othmer, Encyclopedia of Chemical Technology, Third Edition,
vol. 21, Styrene, pp. 770-801. .
Ward, D. J., et al., Hydrocarbon Processing, vol. 66, No. 3, Mar.
1987, pp. 47-48. .
Kimble, James B. and John H. Kolts, "Oxidative Coupling of Methane
to Higher Hydrocarbons", Energy Progress, vol. 6, p. 227 (1986).
.
Driscoll, D. J., W. M. Martir, J. Wang and J. H. Lunsford, J. Am.
Chem. Soc. 107, 58-63 (1985). .
Ito, T., J. Wang, C. Lin and J. H. Lunsford, J. Am. Chem. Soc. 107,
5062-64 (1985). .
Illingworth, G. F. and G. W. Lester, ACS Petroleum Division
Preprints, 12, No. 3, 161 (1967). .
Lee, K. W., M. J. Choi, S. B. Kim and C. S. Choi, Ind. Eng. Chem.
Res. 26, 1951 (1987). .
Kegeyan, E. M., I. S. Vardanyan and A. B. Nalbandyan, Kinetics and
Catalysis 17, No. 4, 749-754 and No. 755-759 (1976). .
Fiedorow, R., W. Przystajko, M. Sopa and I. G. Dalla Lana, The
Nature and Catalytic Influence of Coke on Alumina: Oxidative
Dehydration of Ethylbenzene, Journal of Catalysis 68, pp. 33-41
(1981). .
Vrieland, G. E., Oxydehydration of Ethylebenzene to Styrene Over
Metal Phosphates, Journal of Catalysis 111, pp. 1-13
(1988)..
|
Primary Examiner: Shine; W. J.
Attorney, Agent or Firm: Speckman; Thomas W.
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of copending U.S. Patent
Applications, Ser. Nos. 274,415; 274,499; and 274,454, all filed
Nov. 21, 1988 as continuations-in-part of U.S. Patent Application,
Ser. No. 172,808, filed Mar. 28, 1988, now U.S. Pat. No. 4,826,796
.
Claims
We claim:
1. A mixed basic metal sulfide catalyst having the formula:
wherein
A is an alkali metal selected from lithium, sodium, potassium,
rubidium, cesium and mixtures thereof;
B is a cation which has an ionization state 1 greater than the
ionization state of C;
B is selected from scandium, yttrium, lanthanum, actinium,
aluminum, boron and mixtures thereof when C is selected from
beryllium, magnesium, calcium, strontium, barium, radium, zinc,
cadmium, mercury and mixtures thereof and
B is selected from titanium, zirconium, hafnium, silicon and
mixtures thereof when C is selected from scandium, yttrium,
lanthanum, actinium, aluminum, boron and mixtures thereof;
x and y are in mole fractions of z such that when z=1 then x=0.001
to 0.25, and y=0.001 to 0.25; and
q is a number necessary to maintain charge balance with S being
sulfur.
2. A catalyst according to claim 1 wherein B is selected from the
group consisting of boron, aluminum, yttrium, lanthanum, and
mixtures thereof and C is selected from the group consisting of
magnesium, calcium, barium, zinc and mixtures thereof.
3. A catalyst according to claim 1 wherein B is selected from the
group consisting of silicon, titanium, zirconium, hafnium, and
mixtures thereof and C is selected from the group consisting of
boron, aluminum, yttrium, lanthanum, and mixtures thereof.
4. A catalyst according to claim 1 wherein x=0.05 to 0.15 and
y=0.002 to 0.20.
5. A catalyst according to claim 1 wherein said A is selected from
the group consisting of lithium sodium and potassium and is present
in about 0.5 to about 8 mole percent, said B is boron and is
present in about 0.4 to about 2 mole percent, and the remainder
being C selected from the group consisting of magnesium, calcium,
barium, and zinc.
6. A catalyst according to claim 1 wherein A is lithium.
7. A catalyst according to claim 1 wherein C is magnesium.
8. A catalyst according to claim 1 wherein A is lithium and C is
magnesium.
9. A catalyst according to claim 1 wherein B is boron and is
present in about 0.2 to about 20 mole percent.
10. A catalyst according to claim 9 wherein A is lithium.
11. A catalyst comprising mixed basic metal sulfide having the
formula: xA.yB.zC.qS, wherein A is an alkali metal selected from
lithium, sodium, potassium, rubidium, cesium and mixtures thereof;
B is a cation which has an ionization state 1 greater than the
ionization state of C; B is selected from scandium, yttrium,
lanthanum, actinium, aluminum, boron and mixtures thereof when C is
selected from beryllium, magnesium, calcium, strontium, barium,
radium, zinc, cadmium, mercury and mixtures thereof; and B is
selected from titanium, zirconium, hafnium, silicon and mixtures
thereof when C is selected from scandium, yttrium, lanthanum,
actinium, aluminum, boron and mixtures thereof; x and y are in mole
fractions of z such that when z=1 then x=0.001 to 0.25, and y=0.001
to 0.25; and q is a number necessary to maintain charge balance
with S being sulfur; in admixture with mixed basic metal oxide
having the formula: x'A'.y'B'.z'C'.q'O wherein A' is an alkali
metal selected from lithium, sodium, potassium, rubidium, cesium
and mixtures thereof; B' is a cation which has an ionization state
1 greater than the ionization state of C'; B' is selected from
scandium, yttrium, lanthanum, actinium, aluminum, boron and
mixtures thereof when C' is selected from beryllium, magnesium,
calcium, strontium, barium, radium, zinc, cadmium, mercury and
mixtures thereof and B' is selected from titanium, zirconium,
hafnium, silicon and mixtures thereof when C' is selected from
scandium, yttrium, lanthanum, actinium, aluminum, boron and
mixtures thereof; x' and y' are in mole fractions of z' such that
when z'=1 then x'=0.001 to 0.25, and y'=0.001 to 0.25; and q' is a
number necessary to maintain charge balance with 0 being
oxygen.
12. A mixed sulfide and oxide catalyst according to claim 11
wherein said mixed basic metal sulfide comprises greater than about
50 weight percent of said catalyst.
13. A mixed sulfide and oxide catalyst according to claim 1 wherein
said mixed basic metal sulfide comprises about 75 to 100 weight
percent of said catalyst.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sulfur tolerant mixed basic metal sulfide
catalysts useful for production of higher hydrocarbons by oxidative
coupling of methane, production of higher hydrocarbons by oxidative
coupling of aliphatic and alicyclic hydrocarbon compounds with
aliphatic and alicyclic substituted aromatic hydrocarbon compounds
to form a longer substituent hydrocarbon on the aromatic ring, and
production of unsaturated aliphatic and alicyclic chains by
dehydrogenation of aliphatic and alicyclic hydrocarbon compounds
and aliphatic and alicyclic substituted aromatic hydrocarbon
compounds. Reaction of methane with oxygen in the presence of a
mixed basic metal sulfide catalyst in accordance with this
invention results in high conversion of methane with selectivity
for ethane and ethylene products. Reaction of methane with toluene
and oxygen in the presence of a mixed basic metal sulfide catalyst
according to this invention results in high conversion to form
styrene. One important dehydrogenation is the reaction of
ethylbenzene in the presence of a mixed basic metal sulfide
catalyst according to this invention to produce styrene.
2. Description of the Prior Art
Methane is currently available in large quantities from natural
gas, anaerobic digestion of organic material, and chemical
processing sources. However, use of methane as a chemical feedstock
has been limited due to its high stability. It has been highly
desirable to develop a catalyst for such reactions to enable
operation under milder conditions with greater control over
thermodynamic and kinetic processes as well as provide product
selectivity and high reaction rate.
Oxidative coupling of methane to form higher hydrocarbons has been
shown to be effected over a number of metal oxides, but yields of
desired products have been low, as discussed by Keller, G. E. and
M. M. Bhasin, J. of Catalysis 73, 9-19 (1982). Sodium and lead on
alumina has been found to catalyze the formation of ethane and
ethylene from methane, as disclosed in Hinsen, W. and M. Baerns,
Chem.-Ztg., 107, 223-226 (1983) and Hinsen, W., W. Bytyn and M.
Baerns, Proc. 8th Int. Congr. Catal., Berlin, III 581-592 (1984).
Several U.S. patents teach a series of supported metal oxides which
while effective for the conversion of methane to ethane and
ethylene, are based on reducible metal oxides and used in a
stoichiometric fashion by alternately exposing them to an oxidizing
atmosphere and then to methane in the absence of oxygen. U.S. Pat.
Nos. 4,443,644; 4,443,645; 4,443,646; 4,443,647; 4,443,648;
4,443,649; 4,444,984, 4,499,322; 4,499,323; 4,499,324; and
4,523,049.
Later work has demonstrated that magnesium oxide and calcium oxide,
when promoted with alkali metal salts, are active for oxidative
coupling of methane to ethane and ethylene in the presence of
oxygen. See Kimble, James B. and John H. Kolts, "Oxidative Coupling
of Methane to Higher Hydrocarbons", Energy Progress, Vol. 6, p. 227
(1986); Driscoll, D. J., W. M. Martir, J. Wang and J. H. Lunsford,
J. Am. Chem. Soc. 107, 58-63 (1985); and Ito, T., J. Wang, C. Lin
and J. H. Lunsford, J. Am. Chem. Soc. 107, 5062-64 (1985). These
later catalysts have the advantage of operating continuously, not
requiring regeneration or pretreatment.
Borates and boron compounds have been used in partial oxidation of
hydrocarbons, such as boric acid to oxidize long chain normal
paraffins in the liquid phase (Illingworth, G. F. and G. W. Lester,
ACS Petroleum Division Preprints, 12, No. 3, 161 (1967)) and
oxidation of n-dodecane in the liquid phase to the corresponding
alcohol (Lee, K. W., M. J. Choi, S. B. Kim and C. S. Choi, Ind.
Eng. Chem. Res. 26, 1951 (1987)). Boric acid has been used by
coating reactor walls in the combustion of methane to eliminate
free radical destruction at temperatures of less than 513.degree.
C. (Kegeyan, E. M., I. S. Vardanyan and A. B. Nalbandyan, Kinetics
and Catalysis 17, No. 4,749-754 and No. 4,755-759 (1976))
A number of publications describe oxidative methylation of toluene
performed in Russia: Chemical Abstracts 97:127153K (1982) teaches
non-catalytic methylation of toluene depended mostly on pressure
and PhMe/O/CH.sub.4 molar ratio; Chemical Abstracts 99:70137t
(1983) teaches oxidative methylation of toluene using a Ni-V oxide
or V oxide catalyst; Chemical Abstracts 101:74734t (1984) teaches
oxidative methylation of toluene in presence of 0 (max. 15 percent
in reaction mixture) results in products including styrene;
Chemical Abstracts 101:38205 n (1984) teaches simultaneous
production of styrene, ethylbenzene, benzene, and phenols by
reaction of toluene with C.sub.1-4 alkanes in the presence of O and
Fe.sub.2 O.sub.3 or TiO.sub.2 at 600.degree.-800.degree. .
Productivity increased at higher pressure in presence of H.sub.2
O.sub.2 and/or (Me.sub.3 C).sub.2 O.sub.2 ; and U.S. Pat. No.
3,830,853 teaches reaction of toluene with a lower paraffin
hydrocarbon in the presence of oxygen at 600.degree.-900.degree. C.
and space velocity of 2000-10000 hour.sup.- 1.
Styrene is an important commercial unsaturated aromatic monomer
used extensively in the manufacture of plastics by polymerization
and copolymerization. On a commercial scale, the great majority of
the world's styrene is produced by dehydrogenation of ethylbenzene.
A review of styrene synthesis processes is given in Kirk-Othmer,
Encyclopedia of Chemical Technology, Third Edition, Vol. 21,
Styrene, pgs. 770-801. One commercial process for production of
styrene is the UOP Styro-Plus process using ethylbenzene and
superheated steam under vacuum for the catalytic dehydrogenation of
ethylbenzene as taught by Ward, D. J. et al, Hydrocarbon
Processing, Vol. 66, No. 3, March 1987, pgs 47-48. Use of
coke-covered alumina and boron/alumina catalysts for oxidative
dehydrogenation of ethylbenzene is taught by Fiedorow, R., W.
Przystajko, M. Sopa and I. G. Dalla Lana, The Nature and Catalytic
Influence of Coke on Alumina: Oxidative Dehydrogenation of
Ethylbenzene, Journal of Catalysis 68, pgs. 33-41 (1981). Oxidative
dehydrogenation of ethylbenzene to styrene over metal
pyrophosphates, such as cerium, tin, zirconium, and titanium
phosphates and calcium magnesium, strontium, barium, nickel,
aluminum, thorium, zinc and silicon phosphates is taught by
Vrieland, G. E., Oxydehydration of Ethylbenzene to Styrene over
Metal Phosphates, Journal of Catalysis 111, pgs. 1-13 (1988). This
article teaches the condensed phosphate surface is the dominant
factor as a catalyst and that the cation has little or no
effect.
SUMMARY OF THE INVENTION
This invention provides a sulfur tolerant mixed basic metal sulfide
catalyst and catalytic process for oxidative coupling of methane to
produce higher molecular weight hydrocarbons. A mixed basic metal
oxide catalyst and its use in these proceses is fully described in
copending and commonly owned U.S. Patent Application, Mixed Basic
Metal Oxide Catalyst for Oxidative Coupling of Methane, Ser. No.
07/274,415, filed Nov. 21, 1988. Oxidative coupling of aliphatic
and alicyclic hydrocarbons with aliphatic and alicyclic substituted
aromatic hydrocarbons using the same mixed basic metal oxide
catalyst is fully described in copending and commonly owned U.S.
Patent Application, Oxidative Coupling of Aliphatic and Alicyclic
Hydrocarbons With Aliphatic and Alicyclic Substituted Aromatic
Hydrocarbons, Ser. No. 07/274,454, filed Nov. 21, 1988.
Dehydrogenation of saturated hydrocarbon chains using the same
mixed basic oxide catalyst is fully described in copending and
commonly owned U.S. Patent Application, Dehydration of Aliphatic
and Alicyclic Hydrocarbons and Aliphatic and Alicyclic Substituted
Aromatic Hydrocarbons, Ser. No. 07/274,499, filed Nov. 21, 1988.
The above copending commonly owned U.S. Patent Applications are
continuations-in-part of U.S. Patent Application, Ser. No. 172,808,
filed Mar. 28, 1988, now U.S. Pat. No. 4,826,796. The above
commonly owned U.S. Patent Applications and Patent are fully
incorporated herein by reference. The above U.S. Patent
Applications teach mixed basic metal oxide catalysts of the formula
xA.yB.zC.qO wherein 0 is oxygen, A, B and C represent the same
chemical elements and x, y, z and q represent the same numerals as
the corresponding symbols do in the following formula for mixed
basic metal sulfide catalysts of this invention. The mixed basic
metal sulfide catalyst of this invention provides sulfur tolerance
which allows effective utilization of sulfur containing feedstocks
as derived from naturally occurring carbonaceous materials.
The mixed basic metal sulfide catalyst of this invention has the
formula:
wherein
A is an alkali metal selected from lithium, sodium, potassium,
rubidium, cesium and mixtures thereof;
B is a cation which has an ionization state 1 greater than the
ionization state of C;
B is selected from scandium, yttrium, lanthanum, actinium,
aluminum, boron, and mixtures thereof from Group IIIA and IIIB of
the Periodic Table, preferably boron, aluminum, yttrium, lanthanum,
and mixtures thereof when C is selected from beryllium, magnesium,
calcium, strontium, barium, radium, zinc, cadmium, mercury and
mixtures thereof from Group IIA and IIB of the Periodic Table,
preferably magnesium, calcium, barium, zinc, and mixtures thereof,
and
B is selected from titanium, zirconium, hafnium, silicon and
mixtures thereof from Group IVA and IVB of the Periodic Table, when
C is selected from scandium, yttrium, lanthanum, actinium,
aluminum, boron and mixtures thereof from Group IIIA and IIIB of
the Periodic Table, preferably boron, aluminum, yttrium, lanthanum,
and mixtures thereof;
x and y are in the mole fractions of z such that when z=1 then
x=0.001 to 0.25, preferably 0.05 to 0.15 and y=0.001 to 0.25,
preferably 0.002 to 0.20; and
q is a number necessary to maintain charge balance with S being
sulfur.
The above mixed basic metal sulfide catalyst may be used in any
mixture with the mixed basic metal oxide catalyst set forth in the
parent applications.
In a preferred embodiment, a boron/alkali metal promoted metal
sulfide catalyst having boron in amounts of about 0.2 to about 20
mole percent (about 0.05 to about 5.0 weight percent), alkali metal
promoter selected from the group consisting of lithium, sodium and
potassium in amounts of about 0.1 to about 25 mole percent (about
0.1 to about 40 weight percent), metal sulfide selected from the
group consisting of magnesium sulfide, calcium sulfide, zinc
sulfide, and barium sulfide.
This invention provides a catalyst for oxidative coupling of
methane to produce a higher molecular weight hydrocarbon and for
oxidative coupling of aliphatic and alicyclic hydrocarbon compounds
with aliphatic and alicyclic substituted aromatic hydrocarbon
compounds to produce a longer substituent hydrocarbon on the
aromatic ring. The reaction of an aliphatic or alicyclic
hydrocarbon compound with an aliphatic or alicyclic substituted
aromatic hydrocarbon compound and oxygen is conducted in the
presence of a mixed basic metal sulfide catalyst at elevated
temperature according to the following general reaction: ##STR1##
wherein R is an aliphatic or alicyclic hydrocarbon radical; and R'
is an aliphatic or alicyclic hydrocarbon radical substituted on
anaromatic hydrocarbon ring.
It is unexpected that catalysts active for oxidative coupling as
described above involving carbon-carbon bond formation would also
be active for dehydrogenation involving carbon-hydrogen bond
breaking with subsequent carbon-carbon double bond formation.
Dehydrogenation of saturated organics has been described by Thomas,
Charles L, Catalytic Processes and Proven Catalysts, Chap. 6,
Dehydrogenation, pgs. 41-45, Academic Press (1970).
This invention provides a catalyst and process for dehydrogenation
of aliphatic and alicyclic chains of aliphatic and alicyclic
hydrocarbon compounds and aliphatic and alicyclic substituted
aromatic hydrocarbon compounds to produce an unsaturation in the
hydrocarbon chain. The reaction of an aliphatic or alicyclic
hydrocarbon compound, an aliphatic or alicyclic substituted
aromatic hydrocarbon compound and mixtures thereof in the
dehydrogenation reaction is conducted in the presence of a mixed
basic metal sulfide catalyst at elevated temperature. The
dehydrogenation may proceed directly according to the following
general reaction of C--C bonding in a compound RH or R'CH.sub.3
being converted to C.dbd.C bonding +H.sub.2 or may proceed by
oxidative dehydrogenation wherein C--C bonding in a compound RH or
R'CH.sub.3 +1/2 O.sub.2 is converted to C.dbd.C bonding +H.sub.2 O,
wherein R is an aliphatic or alicyclic hydrocarbon radical having 2
and more carbon atoms; and R' is an aliphatic or alicyclic
hydrocarbon radical substituted on an aromatic hydrocarbon ring. In
the case of dehydrogenation of ethylbenzene to styrene according to
this invention, direct dehydrogenation proceeds according to the
general reaction: ##STR2## and by partial oxidation or oxidative
dehydrogenation according to the general reaction: ##STR3##
The mixed basic metal sulfide catalyst of this invention provides a
catalyst which is tolerant of sulfer containing reactant compounds.
Such sulfur tolerance is important when using hydrocarbon reactants
derived from natural sources, such as methane obtained from
gasification of coal, shale, and other natural carbonaceous
materials. The maintenance of catalytic activity of the mixed basic
metal sulfide catalyst of this invention in the presence of sulfur
containing materials, such as H.sub.2 S, is of great commercial
importance in view of the high cost of sulfur removal from
hydrocarbons derived from naturally occurring sources.
DESCRIPTION OF PREFERRED EMBODIMENTS
The catalyst of this invention is a mixed basic metal sulfide
catalyst having the formula xA.yB.zC.qS wherein A, B, C, x, y, z
and q have the meanings set forth above with S being sulfur. The
catalysts used in the process of this invention have only one
oxidation state besides the metal, that is Ti, Zr, Hf and Si are
only +4 and B, Al, Y and La are only +3, while Mg, Ca, Sr and Ba
are only +2 and Li, K, Na, Rb and Cs are only +1. In a particularly
preferred embodiment, the catalyst of this invention is a
boron/alkali metal promoted metal sulfide catalyst having boron in
amounts of about 0.2 to about 20 mole percent (about 0.05 to about
5 weight percent) and preferably about 0.4 to about 2 mole percent
(about 0.1 to about 0.5 weight percent); alkali metal promoter
selected from the group consisting of lithium, sodium and potassium
in amounts of about 0.1 to about 25 mole percent (about 0.1 to
about 40 weight percent) and preferably about 0.5 to about 8 mole
percent (about 0.5 to about 2.0 weight percent) and the remainder
metal sulfide selected from the group consisting of magnesium
sulfide calcium sulfide, zinc sulfide, and barium sulfide. A
preferred catalyst is boron/lithium promoted magnesium sulfide
having about 0.8 to about 1.2 weight percent lithium.
The mixed basic metal sulfide catalyst of this invention may be
used in its pure form or may be used in admixture with the mixed
basic metal oxide catalyst described in the above copending
commonly assigned U.S. Patent Applications. When sulfur containing
hydrocarbon feedstocks are used in the reactions catalyzed, it is
preferred that the sulfide catalyst comprise over about 50 percent
by weight of the total sulfide and oxide catalyst, and most
preferably about 75 to about 100 percent. The mixed sulfide and
oxide catalyst comprises mixed basic metal sulfide having the
formula: xA.yB.zC.qS, wherein A is an alkali metal selected from
lithium, sodium, potassium, rubidium, cesium and mixtures thereof;
B is a cation which has an ionization state 1 greater than the
ionization state of C; B is selected from scandium, yttrium,
lanthanum, actinium, aluminum, boron and mixtures thereof when C is
selected from beryllium, magnesium, calcium, strontium, barium,
radium, zinc, cadmium, mercury and mixtures thereof; and B is
selected from titanium, zirconium, hafnium, silicon and mixtures
thereof when C is selected from scandium, yttrium, lanthanum,
actinium, aluminum, boron and mixtures thereof; x and y are in mole
fractions of z such that when z=1 then x=0.001 to 0.25, and y=0.001
to 0.25; and q is a number necessary to maintain charge balance
with S being sulfur; in admixture with mixed basic metal oxide
having the formula: x'A'.y'B'.z'C'.q'O wherein A' is an alkali
metal selected from lithium, sodium, potassium, rubidium, cesium
and mixtures thereof B' is a cation which has an ionization state 1
greater than the ionization state of C'; B' is selected from
scandium, yttrium, lanthanum, actinium, aluminum, boron and
mixtures thereof when C' is selected from beryllium, magnesium,
calcium, strontium, barium, radium, zinc, cadmium, mercury and
mixtures thereof and B' is selected from titanium, zirconium,
hafnium, silicon and mixtures thereof when C' is selected from
scandium, yttrium, lanthanum, actinium, aluminum, boron and
mixtures thereof; x' and y' are in mole fractions of z' such that
when z'=1 then x'=0 001 to 0.25, and y'=0.001 to 0.25; and q' is a
number necessary to maintain charge balance with O being
oxygen.
The sulfide catalyst of this invention may be prepared by making a
liquid solution of one or two soluble compounds of desired metal or
metals and adding it to a metal sulfide powder of the remaining
component or components. Any liquid solutions which will retain the
sulfide compound are satisfactory. For example, an organic liquid
must be used when using magnesium sulfide since an aqueous solution
would cause undesired conversion to the oxide state. A wide variety
of noninterfering ions may be used to form suitable liquid soluble
compounds as long as they do not cause undesired chemical
interference. Suitable such compounds include acids, sulfides,
oxides, hydrides, and nitrates, carbonates, hydroxides. The liquid
solution one or two soluble components is added to metal sulfide
powder of the remaining component or components and well mixed
followed by drying at a sufficient temperature and for a sufficient
time to expel volatile components. The mixture is then crushed and
sieved to a small size for catalytic use. Conventional and well
known catalyst manufacturing techniques may be employed to produce
the catalyst material noted above. When preparing these catalytic
materials, it is preferred to employ manufacturing techniques
resulting in a product having a substantially uniform or
homogeneous composition. Shaping of the material may be effected
according to conventional techniques of the art, particularly
tableting, or pelleting or extrusion. The catalyst may be used
unsupported or alternatively it may be supported on an inert
support as known to the art, such as alumina, silica, activated
carbon and the like.
A 100 percent sulfide catalyst may be prepared by mixing 0.82 grams
Cerac boron sulfide powder, -200 mesh, and 42.0 grams Cerac
magnesium sulfide powder, -200 mesh, in a ceramic dish. 1.02 grams
Aesar 99% lithium sulfide may be added to 30 grams n-propanol and
stirred to obtain complete solution of the solids. The lithium
solution is added to the boron and magnesium powders with stirring
to obtain a homogeneous mixture which may then be dried at a
temperature in excess of about 110.degree. C. The dried mixture may
then be calcined at a temperature of 700.degree. to 750.degree. C.
for a sufficient time, about 2 hours, to expel volatile portions.
The mixture is then crushed and sieved to an appropriately small
mesh size of about -6 to about +40, preferably about -12 to about
+20 for use as a catalyst.
To prepare a mixed sulfide/oxide catalyst, a mixture of 0.43 grams
Aesar 99.99% pure boric acid and 1.07 grams Aesar anhydrous lithium
hydroxide and 30 grams n-propanol are added to a beaker and stirred
to obtain complete solution of the solids. The solution is slowly
added to 42.0 grams Cerac magnesium sulfide powder, -200 mesh, to
obtain a homogeneous mixture which may be dried, calcined, and
crushed.
This invention provides gas phase oxidative coupling of methane by
reaction of methane and oxygen in the presence of the above
described mixed basic metal sulfide catalyst, such as a
boron/alkali metal promoted metal sulfide catalyst. Feedstock gas
comprising methane suitable for use in the process of this
invention may comprise any methane containing gas which does not
contain interfering compounds. Preferably, the methane containing
gas used in the process of this invention comprises about 25 mole
percent up to about 100 mole percent methane. Suitable sources of
methane containing gas include natural gas, synthetic natural gas
(SNG), product gas from gasification of carbonaceous materials,
such as gasification of coal, peat, shale, and the like, as well as
products of anaerobic digestion of various biomass materials These
gases principally comprise methane and may contain other
hydrocarbon gases such as ethane and propane which may produce
corresponding chemical reactions to those of methane in the process
of this invention. Purification of such mixed gases comprising
principally methane is not usually necessary, especially when using
the sulfur tolerant basic metal sulfide catalyst of this invention.
These sources of methane containing gas and processes for producing
methane are well known in the art. The term "methane" as used
throughout this disclosure and claims refers to methane as
described above.
Any oxygen containing gas not containing interfering chemical
compounds are useful as a feedstock in oxidative coupling according
to this invention. The term "oxygen containing gas" as used
throughout this disclosure and claims, refers to gas containing
oxygen, such as air and gases having an oxygen content of up to 100
percent. It is preferred to use oxygen containing gas comprising
over 50 volume percent oxygen. The mole percentage of oxygen
relative to the mole percentage of methane in the gas mixture
subjected to the process of this invention is about 2 to about 40
and preferably about 5 to about 20 mole percent oxygen.
The catalyst may be placed into a reactor, such as a tube-shell
fixed bed, fluidized bed, moving bed, inter-bed heat exchange type,
Fischer-Tropsch type, or other reactor type known to the art.
Suitable reactor vessels for use at the desired operating
temperatures and pressures are well known to the art. The reaction
of methane and oxygen according to this invention is carried out by
passing a gaseous mixture comprising methane and oxygen over the
mixed basic metal sulfide catalyst as defined above at about
500.degree. to about 1100.degree. C., preferably about 600.degree.
to about 900.degree. C. Suitable gas residence times are about
0.002 to about 0.00002 hour preferably about 0.0005 to about 0.0001
hour. The reaction may be carried out at about pressures of about 1
to about 1515 psia, preferably about 1 to about 150 psia.
The catalyst of this invention provides a longer hydrocarbon
substituent on an aromatic ring by gas phase oxidative coupling of
saturated carbon atoms of an aliphatic or alicyclic hydrocarbon
compound with an aliphatic or alicyclic substituted aromatic
hydrocarbon and oxygen. Suitable aliphatic and alicyclic
hydrocarbon compounds for use as feedstocks in the process of this
invention include straight and branched chain saturated and
unsaturated aliphatic hydrocarbons, such as methane, ethane,
propane, butane, heptane, pentane, hexane, octane, isobutane,
isohexane, isooctane, 1-pentene, 1-hexene and mixtures thereof;
cyclic chain saturated and unsaturated alicyclic hydrocarbons, such
as cyclobutane, cycloheptane, cycloheptene, cyclohexane,
cyclohexene and mixtures thereof; and aryl substituted aliphatic
and alicyclic hydrocarbons, such as toluene, xylene, mesitylene,
durene, cumene and mixtures thereof. In the case of unsaturated
hydrocarbons, it should be noted that the oxidative coupling of
this invention does not occur at the unsaturated bonding. Suitable
aliphatic and alicyclic substituted aromatic hydrocarbon compounds
for use as feedstocks in this invention are aromatic ring
hydrocarbons having at least one aliphatic or alicyclic hydrocarbon
radical substituent on the aromatic ring, such as toluene, xylene,
indan, tetralin, and mixtures thereof.
The reactants are fed to the reaction zone in mole percent
proportions of about 50 to about 90 mole percent aliphatic or
alicyclic hydrocarbon compounds, preferably about 75 to about 85
mole percent; about 2 to about 40 mole percent substituted aromaric
hydrocarbon, preferably about 5 to about 15 mole percent; and about
2 to about 20 mole percent oxygen, preferably about 5 to about 12
mole percent. Steam may be added in an amount of up to about 1 mole
of steam per mole hydrocarbon to inhibit deep oxidation. Steam does
not enter into the reaction but solely acts as an oxidation
inhibitor. It is preferred to use oxygen containing gas comprising
over 50 volume percent oxygen. The amounts of oxygen used in the
oxidative coupling of aliphatic and alicyclic hydrocarbons with
aromatic hydrocarbons are expressed as pure oxygen. The oxygen
containing gas may be preheated by thermal exchange with the
catalyst bed to a temperature suitable for the reaction controlling
step of the process. An important aliphatic feedstock suitable for
use in the process of this invention may comprise methane as
described above. Important substituted aromatic feedstocks include
toluene and xylene available from commercial sources.
The oxidative coupling is carried out by passing the gaseous
aliphatic or alicyclic hydrocarbon and aromatic feedstocks and
oxygen over the mixed basic metal sulfide catalyst as defined above
at about 300.degree. to about 1100.degree. C., preferably about
600.degree. to about 900.degree. C. Suitable gas residence times
are about 0.002 to about 0.00002 hour preferably about 0.0005 to
about 0.0001 hour with space velocity of about 500 to about 50,000
vol/vol/hr, preferably about 1000 to about 5000 vol/vol/hr. The
reaction may be carried out at about pressures of about 1 to about
1515 psia, preferably about to about 150 psia, pressures above
atmospheric may enhance the rate of reaction. Suitable reactor
vessels for use at the above operating temperatures and pressures
are well known to the art. The products of the single reactor used
in the process of this invention may be passed to a simple
separator for separation of the hydrocarbon product, condensate,
and vent gas.
One important oxidative coupling reaction according to the process
of this invention is the production of styrene directly by coupling
of toluene and methane by the following reaction in the presence of
the above defined catalyst: ##STR4## At 750.degree. C. the heat of
reaction (.DELTA.H) is -73 kcal/mole and the sensible heat plus the
heat of vaporization of toluene is about 55 kcal/mole. Thus the
process operates close to autothermal conditions after initial
light-off. Conventional processes using Fe.sub.2 O.sub.3 as a
catalyst with Cr.sub.2 O.sub.3 as a stabilizer and K.sub.2 CO.sub.3
as a coke retardant for production of styrene require ethylbenzene
feedstock, produced from expensive benzene and ethylene and require
large amounts of superheated steam (800.degree. C. and molar ratio
14 steam to 1 ethylbenzene) due to the conversion of ethylbenzene
to styrene being endothermic The process of this invention uses
relatively inexpensive toluene, methane and air as feedstock to a
single reactor where both styrene and ethylbenzene are produced in
a process that does not require superheated steam.
The catalyst of this invention provides unsaturated aliphatic and
alicyclic chains by dehydrogenation of saturated carbon atoms of an
aliphatic or alicyclic hydrocarbon compound and an aliphatic or
alicyclic substituted aromatic hydrocarbon and mixtures thereof.
Suitable aliphatic and alicyclic hydrocarbon compounds for use as
feedstocks in the process of this invention include straight and
branched chain saturated aliphatic hydrocarbons, such as ethane,
propane, butane, heptane, pentane, hexane, octane, isobutane,
isohexene, isooctane and mixtures thereof; cyclic chain saturated
alicyclic hydrocarbons, such as cyclobutane, cycloheptane,
cyclohexane and mixtures thereof. Suitable aliphatic and alicyclic
substituted aromatic hydrocarbon compounds for use as feedstocks in
this invention are aromatic ring hydrocarbons having at least one
saturated aliphatic or alicyclic hydrocarbon radical substituent on
the aromatic ring, such as ethylbenzene, indan, tetralin and
mixtures thereof.
The hydrocarbon reactant is fed to the reaction zone in contact
with the above defined catalyst for direct dehydrogenation and for
oxidative dehydrogenation. For oxidative dehydrogenation oxygen may
be added up to a mole amount of about 5 moles oxygen per mole
hydrocarbon, preferably about 0.5 to about 2.0 moles oxygen per
mole hydrocarbon. Steam may be added in an amount of up to about 1
mole of steam per mole hydrocarbon to inhibit undesired side
reactions when oxygen is used in the feed for oxidative
dehydrogenation. Steam does not enter into the reaction but solely
acts as an oxidation inhibitor. For direct dehydrogenation, without
oxygen in the feed, steam may be used as a heat carrying agent and
up to 10 moles of steam per mole of hydrocarbon may be
required.
The dehydrogenation process according to this invention is carried
out by passing the gaseous aliphatic or alicyclic hydrocarbon or
aromatic feedstock over the mixed basic metal sulfide catalyst is
defined above at a space velocity of about 500 to about 50,000
vol/vol/hr providing gas residence times of about 0.002 to about
0.00002 hour preferably about 0.0002 to about 0.00007 hour.
Suitable temperatures are about 200.degree. to about 1000.degree.
C., preferably about 600.degree. to about 850.degree. C. for direct
dehydrogenation and preferably about 450.degree. to about
700.degree. C. for oxidative dehydrogenation. The reaction may be
carried out at pressures of about 1 psia to about 1515 psia,
preferably about 1 psia to about 25 psia for direct dehydrogenation
and preferably about 1 psia to about 150 psia for oxidative
dehydrogenation. Pressures above atmospheric may enhance the rate
of reaction. Suitable reactor vessels for use at the above
operating temperatures and pressures are well known to the art. The
products of the single reactor used in the process of this
invention may be passed to a simple separator for separation of the
hydrocarbon product, condensate, and vent gas.
One important dehydrogenation reaction according to the process of
this invention is the production of styrene directly by
dehydrogenation of ethylbenzene or by oxidative dehydrogenation of
ethylbenzene in the presence of the above defined catalyst
according to the reactions set forth above. At 727.degree. C. the
heat of reaction (.DELTA.H) for oxidative dehydrogenation is -29.4
kcal/mole exothermic and the sensible heat plus the heat of
vaporization of ethylbenzene is about 33.0 kcal/mole. Thus the
oxidative dehydrogenation process operates close to autothermal
conditions after initial light-off. Conventional processes for
production of styrene from ethylbenzene feedstock require large
amounts of superheated steam (800.degree. C. and molar ratio 14
steam to 1 ethylbenzene) because the conversion of ethylbenzene to
styrene is endothermic. The dehydration process of this invention
uses a single reactor in a process that does not require
superheated steam.
While in the foregoing specification this invention has been
described in relation to certain preferred embodiments thereof, and
many details have been set forth for purpose of illustration, it
will be apparent to those skilled in the art that the invention is
susceptible to additional embodiments and that certain of the
details described herein can be varied considerably without
departing from the basic principles of the invention.
* * * * *